Re: Something flaky in the "relfilenode mapping" infrastructure

Andres Freund <andres@2ndquadrant.com> writes:
> On 2014-06-12 00:38:36 -0400, Noah Misch wrote:
>> http://buildfarm.postgresql.org/cgi-bin/show_log.pl?nm=prairiedog&dt=2014-06-12%2000%3A17%3A07

> Hm. My guess it's that it's just a 'harmless' concurrency issue. The
> test currently run in concurrency with others: I think what happens is
> that the table gets dropped in the other relation after the query has
> acquired the mvcc snapshot (used for the pg_class) test.
> But why is it triggering on such a 'unusual' system and not on others?
> That's what worries me a bit.

prairiedog is pretty damn slow by modern standards.  OTOH, I think it
is not the slowest machine in the buildfarm; hamster for instance seems
to be at least a factor of 2 slower.  So I'm not sure whether to believe
it's just a timing issue.
        regards, tom lane